Watch your mouth: sage advice from St. James.

It wouldn't be hard to compile a "Greatest Hits" album of recent official Catholic teaching on moral questions. Sexual Ethics (Humanae vitae), human rights (Gaudium et spes), abortion and euthanasia (Evangelium vitae), just-war theory (The Challenge of Peace), economic justice (Economic Justice for All), and the role of women (Mulieris dignitatem). Wherever we stand on the issues, most of us are familiar with the playlist.

Maybe the band should add a new number to its repertoire. Perhaps we need a retrosound--a really retro sound. Take the Epistle of James. No one could accuse its author of being soft on morals; in fact, Luther called it a "right strawy epistle" because he thought it emphasized good works at the expense of faith. There's little overlap between James's playlist and ours. In fact, the topic that most agitates him is virtually invisible today: the power of the tongue. And by that he doesn't mean the farewell tour of the Rolling Stones. He means the human capacity--and propensity--to talk. Our drive to communicate is at least as powerful as our sex drive. According to James, it is just as dangerous.

James observes, "Consider how small a fire can set a huge forest ablaze. The tongue is also a fire. It exists among our members as a world of malice, defiling the whole body and setting the entire of our lives on fire, itself set on fire by Gehenna. For every kind of beast and bird, of reptile and sea creature, can be tamed and has been tamed by the human species, but no human being can tame the tongue. It is a restless evil, full of deadly poison. With it we bless the Lord and Father, and with it we curse human beings who are made in the likeness of God."

Not a comforting passage for members of the chattering classes. Blog impresarios and mavens of the print media can't escape on the technicality that their instrument is the keyboard, not the tongue--they bless and curse with the best of them. James's warning to teachers--those who make their living by talking--is explicit and dire. More broadly, though, his message is deeply disconcerting for all of us Americans who view cell phones and instant messaging as important new recreational devices.

James is not primarily concerned with abstract questions, like the tension between freedom of expression and community values. His focus is the concrete effect that certain types of speech have on the speaker and the community. First, he thinks that people who spend too much time talking about faith, holiness, and good works won't put their money where their mouth is. Second, he worries that these talkers will judge themselves by their words, and other people by their deeds, leading to self-righteousness. James writes, "There is one lawgiver and judge who is able to save and destroy. Who then are you to judge your neighbor?" Third, James is well aware that loving one's neighbors is not compatible with running them down behind their backs. More than a millennium later, Aquinas builds on James's insights. He devotes five separate questions of the Summa Theologiae to "injuries inflicted by words": reviling, backbiting, talebearing, derision, and cursing. Not only does Aquinas emphasize that these practices are violations of justice, he explicitly warns that they can be mortal sins.

But James's ultimate concern seems to be the fragile unity of his community. Nothing short of bullets is more destructive of communal well-being and solidarity than destructive talk--even if it is true. Gossip travels, feelings get hurt, and loyalties get betrayed. Sometimes lives are destroyed. Sides are formed. More energy is put into the conversation about the fractures in the community than into the healing of them.

We see this ourselves, in families, in schools, in workplaces, in the country, and in the church. Sometimes we are overwhelmed with information which is arguably more salacious than relevant. Do we need to know whether anorexia nervosa is Mary-Kate Olsen's sole "health problem," or whether it also includes addiction to cocaine, as some tabloids claim? Was it really necessary to unseal court records of Jack Ryan's messy divorce to assess his fitness to represent Illinois in the U.S. Senate? Do we need every detail? In the church, liberals and conservatives quickly blamed the root causes of the sexual-abuse crisis on each other, with no compunction against battering the already bruised body of Christ in service of their own political agendas.

What should we do now? That's a hard question, and it deserves more systematic attention. Things aren't as straightforward as in James's time. We live in a democratic republic requiring public deliberation about the common good. We know that silence can be used to conceal injustice, and that truth-telling can sometimes be a necessary liberation. What's the difference between fraternal correction and sinful reviling of another? There are delicate lines to be drawn--just as in matters of sexual morality. James's own strategy, "everyone should be quick to hear, slow to speak, and slow to wrath," is good advice. But it is a hard sell in this culture. Everyone says that the monastic vow of perpetual chastity is the hardest for Americans to accept. I think most people would find it a piece of cake next to the vow of perpetual silence.

Cathleen Kaveny teaches law and theology at the University of Notre Dame.